We propose to develop and test an occupational history questionnaire, possibly computer assisted, which will collect both routine occupational information and detect data concerning specific exposures in chosen occupations and industries of suspected high risk. We wish to design the system so as to be compatible with the Centralized Cancer Patient Data System currently in operation at nineteen Comprehensive Cancer Centers. We will test the validity and reliability of the occupational data collected by the questionnaire and will demonstrate the system to the Comprehensive Cancer Centers in order to promote its general adoption by them for specific collaborative research studies.